It becomes popular to incorporate computers in home appliances for their control and information processing along with higher performance and lower cost of small-size computer systems. High-quality contents such as images and sounds including videos and music provided by digital data are being supplied. Multimedia contents containing a mixture of images and sounds are also being spread. Such contents can be easily acquired and enjoyed by recent prevalence of the Internet as a global computer network and the implementation of low-cost mobile communication.
Home video devices are shifting from ones which allow the user to record analog broadcasting programs and enjoy images and music supplied by media to ones which record and play back moving pictures and sounds as high-quality digital data free from any degradation. For example, small-size, low-cost digital video recording apparatuses which can process digital data, and digital video cameras which can be purchased by ordinary people have appeared. Digital video shooting is done in home, and video images can be watched and enjoyed.
This increases opportunities for performing video shooting and editing in home, which have been done by broadcasting companies and the like. Broadcasting companies and the like have advanced devices for performing shooting and editing, and technicians with advanced techniques for performing editing and arrangement which simplify contents. However, no advanced device or technician is prepared in home. Hence, contents shot by a home video camera are rarely edited due to the necessity of an expensive device and advanced editing technique. In addition to moving pictures shot in home, information and contents distributed to home are increased by various media and communication means such as the Internet. Such information and contents are changing to multimedia information and contents including moving pictures and sounds. An information search function for these contents becomes very important.
With growing infrastructures such as the Internet for distributing and providing information, even an individual can provide information, and information including moving pictures and sounds is being provided. In the future, the need for a search function and the like for multimedia information and content information on the Internet are expected to increase. The search function must be easily treated by even a user without any special knowledge.
Further, the latest information and contents can be easily distributed in real time by always-on connection of the Internet or mobile communication. It is very important even for broadcasting companies and the like to efficiently acquire, edit, and retouch the latest images and the like. In this situation, demands have arisen for a function of quickly searching for existing information or contents and reflecting them on new information or contents, and a function of easily editing and processing the contents.
Information such as a moving picture which captures contents changing over time with a large information amount is heavy for accumulation. It is difficult to easily search for the contents of such information. Of digital data, document data allows the computer to easily search for a portion containing a character or word by designating the character or word. As for moving pictures and sounds, it is rare to present completely the same information and cause the computer to search for it. The computer generally searches for a similar portion in some sense. With the current techniques, it is difficult for the computer to understand contents expressed by an image, sound, or the like. It is also very difficult to search for contents.
In this fashion, contents to be processed, such as video contents, are increasing. Easy search, editing, and processing of contents are strongly required.
In this environment, devices which hold the features or characteristics of contents as metadata inside or outside the contents and realize a search function using the information, instead of interpreting a large amount of contents, have appeared.
For example, there is proposed a method of facilitating the search and use of information by adding, as metadata to a content or information such as a moving picture, still picture, or sound, a verbal description such as a keyword or caption representing the contents or features, or nonverval information which describes the feature of an image or sound in a format which can be easily processed by a computer.
As for metadata, common formatting by MPEG-7 and the like is being established. However, metadata have large amounts and vary, and not all the devices can process various large-amount metadata. For this reason, devices which utilize metadata always have a possibility of encountering unknown metadata, but possess only a function of ignoring it.
Along with addition of various metadata, each manufacturer creates by itself a system for storing metadata, or the system is upgraded over and over. As a result, unknown metadata or metadata which cannot be processed due to device specifications appears for another manufacturer or a system of a past version. Even for such metadata, the system must perform basic processing and have at least a copy function; otherwise, it becomes difficult to merely add the metadata to contents.
If contents undergo editing which influences the description of metadata, the metadata may become unavailable. For example, when the color of a given segment of a content is changed to the sepia color, metadata which describes the dominant color of the segment becomes insignificant. If the apparatus which executes editing does not cope with the metadata, this means that ineffective metadata is kept added, failing to correctly use the metadata.
In this way, various multimedia contents such as moving pictures, still pictures, and sounds are assigned metadata and used. In this situation, if a multimedia content is edited and processed, the characteristic or state of the metadata may change, or the metadata may become unavailable.
To solve this problem, there is proposed a system as disclosed in Japanese Patent Laid-Open No. 08-077116. This system comprises a central processing apparatus which determines a processing distribution method using an object (data) and attribute (metadata) in accordance with the attribute and various states in order to execute load distribution using an object-oriented data management method. The processing apparatus can instruct a proper processing portion to execute proper processing. However, the central processing apparatus must be separately prepared in this system, greatly decreasing the degree of freedom in system design and use. Since processing is merely distributed, the determination method of the central processing apparatus must be changed upon adding an object (data) which requires a new processing method.